Grace Smith | August 15, 2022
California hasn’t experienced a megaflood since 1862, but research published on Aug. 12 shows that the nation’s most populous state with over 39 million people is due for another, and climate change could intensify it. California can normally be observed as a water scarcity state with recurring droughts and wildfires, but research in Science Advances said climate change has already doubled the likelihood of disastrous flooding, and this is likely to increase with continuous warming.
The Great Flood of 1862 is considered the biggest flood in modern history. The megastorm 160 years ago destroyed one-third of the state’s property, killed 4,000 people, and caused over 200,000 cows to starve or drown. The flood started with a snowstorm in the Sierra Nevada in Dec. 1861 with 15 feet of snow that fell over California’s eastern mountains. After the snowstorm and for the next 40 days, warm rain and high winds poured in and destroyed homes and streets. Sacramento to the San Joaquin Valley, which is 300 miles long by 20 miles wide, was completely underwater.
Although no one knows exactly when the new megaflood will occur, when it does, atmospheric currents from tropical air near the equator will push water vapor, which will be hundreds of miles wide and thousands of miles long, to the West Coast. This will cause countless weeks of rain and snow, with a predicted two inches of rain per hour in Los Angeles.
Daniel Swain, one of the authors of the study, told the Washington Post that some areas in the state are likely to see 70 to 80 inches of rain, with a few places reaching 100 inches in just 30 days.
Forecasters say there is a 0.5 to 1 percent chance of the flood occurring in any given year but are confident that it will happen. For now, Swain and his work are pushing officials to notice the likelihood and prepare for the disaster.